test: rename regression tests with descriptive file names

Rename the tests appropriately alongside mentioning the subsystem
Also, make a few basic changes to make sure the tests conform
to the standard test structure

- Rename test-regress-nodejsGH-9819 to test-crypto-tostring-segfault
- Rename test-regress-nodejsGH-5051 to test-http-addrequest-localaddress
- Rename test-regress-nodejsGH-5727 to test-net-listen-invalid-port
- Rename test-regress-nodejsGH-5927 to test-tty-stdin-pipe
- Rename test-regress-nodejsGH-6235 to test-v8-global-setter

Refs: nodejs#19105
Refs: https://github.com/nodejs/node/blob/master/doc/guides/writing-tests.md#test-structure

test/parallel/test-regress-GH-9819.js → test/parallel/test-crypto-tostring-segfault.js

@@ -3,6 +3,11 @@ const common = require('../common');
 if (!common.hasCrypto)
   common.skip('missing crypto');
 
+// This test ensures that node doesn't SEGFAULT when either of
+// `crypto.createHash` or `crypto.createHmac` are given an object that defines
+// a throwing `toString`.
+// https://github.com/nodejs/node/issues/9819
+
 const assert = require('assert');
 const execFile = require('child_process').execFile;
 

test/parallel/test-regress-GH-5051.js → test/parallel/test-http-addrequest-localaddress.js

@@ -1,5 +1,10 @@
 'use strict';
 require('../common');
+
+// This test ensures that `addRequest`'s Legacy API accepts `localAddress`
+// correctly instead of accepting `path`.
+// https://github.com/nodejs/node/issues/5051
+
 const assert = require('assert');
 const agent = require('http').globalAgent;
 

test/parallel/test-regress-GH-5727.js → test/parallel/test-net-listen-invalid-port.js

@@ -1,5 +1,10 @@
 'use strict';
 const common = require('../common');
+
+// This test ensures that port numbers are validated in *all* kinds of `listen`
+// calls. If an invalid port is supplied, ensures a `RangeError` is thrown.
+// https://github.com/nodejs/node/issues/5727
+
 const assert = require('assert');
 const net = require('net');
 

test/parallel/test-regress-GH-5927.js → test/parallel/test-tty-stdin-pipe.js

@@ -21,6 +21,10 @@
 
 'use strict';
 require('../common');
+
+// This test ensures piping from `stdin` isn't broken.
+// https://github.com/nodejs/node/issues/5927
+
 const assert = require('assert');
 const readline = require('readline');
 

test/parallel/test-regress-GH-6235.js → test/parallel/test-v8-global-setter.js

@@ -22,4 +22,8 @@
 'use strict';
 require('../common');
 
+// This test ensures v8 correctly sets a property on the global object if it
+// has a setter interceptor in strict mode.
+// https://github.com/nodejs/node-v0.x-archive/issues/6235
+
 require('vm').runInNewContext('"use strict"; var v = 1; v = 2');